Longworth K E, Westgate A M, Grady M K, Westcott J Y, Staub N C
Cardiovascular Research Institute, University of California, San Francisco 94143.
J Appl Physiol (1985). 1992 Dec;73(6):2608-15. doi: 10.1152/jappl.1992.73.6.2608.
We sought to determine whether pulmonary intravascular macrophages are involved in pulmonary vascular sensitivity to intravenously injected particles in sheep. We estimated that newborn lambs have few of these macrophages at birth but develop a 10-fold greater density within 2 wk. Awake, chronically instrumented newborn lambs showed no change in pulmonary vascular driving pressure (pulmonary arterial minus left atrial pressure) after injection of either liposomes [2 +/- 3 (SD) cmH2O; n = 5] or Monastral blue particles (3 +/- 2 cmH2O; n = 6) and showed no net pulmonary production of thromboxane B2, the stable metabolite of the vasoconstrictor thromboxane A2. In contrast, five of those lambs 2 wk later showed both an increase in pulmonary vascular driving pressure after injection of liposomes and Monastral blue (20 +/- 16 and 25 +/- 15 cmH2O, respectively; P < 0.05) and net pulmonary production of thromboxane B2 (171 +/- 103 and 429 +/- 419 pg/ml plasma, respectively; P < 0.05). Older lambs (n = 5) had higher pulmonary uptakes than newborn lambs (n = 6) of radioactive liposomes (47 +/- 13 vs. 12 +/- 10%; P < 0.01) and Monastral blue (53 +/- 6 vs. 21 +/- 10%; P < 0.05). We conclude that pulmonary intravascular macrophages are responsible for the sensitivity of sheep to intravenous foreign particles and are essential for a cascade of processes leading to microvascular injury.
我们试图确定肺血管内巨噬细胞是否参与绵羊对静脉注射颗粒的肺血管敏感性。我们估计新生羔羊出生时这些巨噬细胞数量很少，但在2周内其密度会增加10倍。清醒、长期植入仪器的新生羔羊在注射脂质体[2±3（标准差）cmH₂O；n = 5]或宝蓝色颗粒（3±2 cmH₂O；n = 6）后，肺血管驱动压（肺动脉压减去左心房压）无变化，且肺内血栓素B₂（血管收缩剂血栓素A₂的稳定代谢产物）无净生成。相比之下，2周后这些羔羊中有5只在注射脂质体和宝蓝色颗粒后肺血管驱动压均升高（分别为20±16和25±15 cmH₂O；P < 0.05），且肺内有血栓素B₂的净生成（分别为171±103和429±419 pg/ml血浆；P < 0.05）。较大的羔羊（n = 5）对放射性脂质体（47±13%对12±10%；P < 0.01）和宝蓝色颗粒（53±6%对21±10%；P < 0.05）的肺摄取量高于新生羔羊（n = 6）。我们得出结论，肺血管内巨噬细胞是绵羊对静脉注射外来颗粒敏感性的原因，并且对于导致微血管损伤的一系列过程至关重要。
